The Park Tool Chain Wear Indicator CC-2 offers precise, percent-based readings so you know exactly when to replace a chain before it harms cassettes and chainrings. Designed for professional accuracy and daily shop use, it delivers quick results you can trust.

Using a pivoting gauge and two precision pins, the CC-2 measures chain elongation on modern derailleur drivetrains and displays the result in a clear window. Readings are shown in easy-to-interpret increments, removing guesswork and helping you plan maintenance with confidence.

CC-2 Specs at a Glance

• Compatibility: 512-speed derailleur chains.
• Measurement Scale: 0% to 1.0% with window marks at 0, 0.25, 0.50, 0.75 and 1.0.
• Replacement Guidelines: Replace at or before 0.75% for 59-speed chains, and at or before 0.50% for 1012-speed chains (follow your chain makers specific guidance).
• Operation: Insert the fixed and movable pins into alternate inner/outer plates, press the pivoting gauge lightly until it stops, then read the percentage in the viewing window.
• Pro Tip: New chains may show about 0.25% due to designed link playthis is normal and not actual wear.
• Compatibility Note: For certain 12-speed systems (e.g., some flattop/T-Type designs), Park Tool recommends their CC-4.2 gauge.

Design Benefits

1. Actionable precision: Percent-based results help schedule replacements before costly drivetrain wear occurs.
2. Fast, repeatable checks: Clear window and guided motion minimize user error for consistent readings.
3. Shop-proven workflow: Built for frequent use and quick diagnostics across a wide range of derailleur chains.

Final Take

If you want straightforward, percent-based wear readings to protect performance and parts, the Park Tool CC-2 is a reliable, professional-grade solution for routine chain inspections.